Add a conventions document.

This will contain the style guide (once it's written) and presently
contains the beginnings of a standard example network. The diagram still
needs some work, but all of the important machines are present.
Update package_management_101.rst
This file shouldn't have execute bit set.
Merge pull request #120 from sdaugherty/permfix

This file (netbooting.rst) shouldn't have execute bit set.
Update sysadmin_101.rst

Improve some awkward phrasing/grammar
Update sysadmin_101.rst

Improve awkward phrasing
Update filesystems_101.rst

Correct misspelling.
Update package_management_101.rst

Correct misspellings. Comment about dependency resolution. Remove extraneous apostrophe. Insert omitted words.
Merge pull request #123 from dhutty/master

Correct some misspellings and the like. Minor rewordings.
Merge branch 'topic/apeiron/example-network' of https://github.com/apeiron/curriculum into apeiron-topic/apeiron/example-network
Adds the conventions doc to an index to pass, and adds a link from contributions page
whitespace
adds a todo for @apeiron on topography
workaround for problems with graphviz 2.26.3. not DRY, but passes build
Merge branch 'patch-1' of https://github.com/elacheche/curriculum into elacheche-patch-1

Conflicts:
	package_management_101.rst
Address @ronna's comment on purge option
Introduce mounting, fstab, autofs

Introduces the mount command and some of its options. Takes apart
an /etc/fstab file. Briefly introduces autofs and an
/etc/auto.master file. Autofs has a bit too many prerequisites to
be meaningfully covered here, but it is at least introduced with
an example, and discusses the chain of events during an automount.
cleaning up soft_skills_101/201 and backups
Merge pull request #122 from nibalizer/mount_fstab_autofs

Introduce mounting, fstab, autofs
Merge pull request #125 from unpixie/soft_skills

cleaning up soft_skills_101/201 and backups